Joint injuries may commonly result in the complete or partial detachment of ligaments, tendons, and soft tissues from bone. Tissue detachment may occur in many ways, e.g., as the result of an accident such as a fall, overexertion during a work related activity, during the course of an athletic event, or in any one of many other situations and/or activities. These types of injuries are generally the result of excess stress or extraordinary forces being placed upon the tissues.
In the case of a partial detachment, commonly referred to under the general term “sprain,” the injury frequently heals without medical intervention, the patient rests, and care is taken not to expose the injury to undue strenuous activities during the healing process. If, however, the ligament or tendon is completely detached from its attachment site on an associated bone or bones, or if it is severed as the result of a traumatic injury, surgical intervention may be necessary to restore full function to the injured joint. A number of conventional surgical procedures exist for re-attaching such tendons and ligaments to bone.
One such procedure involves forming aligned femoral and tibial tunnels in a knee to repair a damaged anterior cruciate ligament (“ACL”). In one ACL repair procedure, a ligament graft is associated with a surgical implant and secured to the femur. A common ACL femoral fixation means includes an elongate, hard, metallic “button,” sometimes referred to as a cortical button, having one or more filaments coupled to it. The one or more filaments can be formed into one or more coils or loops sized to receive the ligament graft(s) and allow an adequate length of the graft(s) to lie within the femoral tunnel while providing secure extra-cortical fixation. During procedures that use cortical buttons, the button is typically flipped after it passed through and out of the bone tunnel (e.g., a femoral tunnel) so that the button lies flat on a cortical surface while keeping the loop(s), and thus the graft(s) associated with the loop(s), in the tunnel. When flipping the button, however, the button can impinge on soft tissue disposed between the button and the bone, which can prevent the button from seating properly on the cortical surface and damage the impinged tissue. Further, it can be difficult to know when to “flip” the button. Current solutions to this problem are to measure a length of the bone tunnel and mark the filament associated with the button to indicate to the surgeon when the button is to be flipped, or providing a large enough opening to dispose a visualization device, like an endoscope or laparoscope, at the surgical site to see when the button exits the tunnel and can be flipped.
Another drawback to present devices and methods is that the bone tunnels through which an implant such as a cortical button, and the associated filament(s) and graft(s), pass can often be relatively large to accommodate the size of the implant and the graft(s) at various points during the procedure. A procedure for forming a bone tunnel, such as a femoral tunnel, through which the implant is passed and in which the graft(s) is disposed is illustrated in FIGS. 1A-1D. A bone 100 in which a tunnel 101 (FIG. 1D) is to be formed is illustrated in FIG. 1A. The procedure begins by using a Beath pin to form an initial guide tunnel 102 through an entire thickness of the bone 100, as shown in FIG. 1B, the tunnel 102 having a diameter approximately in the range of about 2 millimeters to about 2.5 millimeters. The Beath pin, which is typically thin and long, can remain disposed within the initial guide tunnel 102 to act as a guidewire to help position additional tools for drilling portions of the tunnel 101 having a larger diameter.
A reamer can be passed over the Beath pin to form a larger, passing tunnel 104 through an entire thickness of the bone 100, as shown in FIG. 1C. The previously formed initial guide tunnel 102 is illustrated in FIG. 1C using a dotted line to provide context of a diameter of the passing tunnel 104 as compared to a diameter of the initial guide tunnel 102. The diameter of the initial guide tunnel 102 is typically too small to have a typical cortical button passed through it, which is why the passing tunnel 104 is formed. A diameter of the passing tunnel 104 can be driven by the size of the width of the cortical button, and thus can be approximately in the range of about 4 millimeters to about 5 millimeters. A portion of the tunnel 101, as shown in FIG. 1D a distal portion 101d that is formed into a graft tunnel 106, can then be further expanded and sized for having one or more grafts disposed in it. A reamer can be used to form the graft tunnel 106. The previously formed initial guide and passing tunnels 102, 104 are illustrated in FIG. 1D using dotted lines to provide context of a diameter of the graft tunnel 106 as compared to diameters of the initial guide and passing tunnels 102, 104. A diameter of the graft tunnel 106 can be based on the size of the graft(s) to be disposed therein, and can be approximately in the range of about 6 millimeters to about 8 millimeters.
Accordingly, it is desirable to have implantable bodies that are designed to sit more consistently and favorably with respect to the cortical surface and not impinge tissue disposed between the body and the bone. It is also desirable to have devices and methods that are designed to limit the number of steps used to form bone tunnels in which the implant(s) and graft(s) are disposed, avoids having to measure and mark components of the implant to assist in visualizing a location of the implant(s), and/or limits the amount of bone removed when forming bone tunnels into which the implants and grafts are passed and/or disposed.